The present invention relates to a control unit for a functional device of a motor vehicle. Moreover, the present invention relates to a motor vehicle.
Corresponding control units are provided for the purpose of operating functional devices of a motor vehicle. These control units can comprise a rotary adjuster or a rotary encoder. Modern rotary adjusters comprise mechanical latching positions in which said rotary adjusters latch along their direction of rotation. These latching positions are perceived by the user or rather the operating person in a haptic manner. In addition, an acoustic signal by way of example a click is often also output. Rotary adjusters of this type are widely used and are used by way of example in climate-control operating parts or in the central input unit in the motor vehicle. Generally, the rotary adjusters are used so as to switch to a specific function. By way of example, the temperature per latching step in a climate-control operating part is increased by a predetermined temperature (by way of example 0.5° C.) or the rate of the impeller unit is increased.
In graphic-based systems, such as a human-machine interface, the rotary adjuster can be used so as to navigate in the display of the human-machine interface. An adjustment of the rotary adjuster by one latching position causes the screen display to displace by one step upwards or downwards. In the case of a navigation system, the adjustment of the rotary adjuster by one latching position can cause the scale of the map display to increase or decrease by one step.
The latching positions of the rotary adjuster are generally produced mechanically using a latching curve or magnetically using magnetic pole pairs. With each latching position, a corresponding electric value is output. In other words, in the case of a rotation into the next latching position, an electrical signal is evaluated by a control device in order to determine the direction of rotation and the number of latching steps or rather clicks. This signal conforms to the latching steps that can be perceived in a haptic manner and in which the rotary adjuster latches or rather remains stably secure after the rotation.
If, in the case of a climate-control operating part, an operating person rotates the rotary adjuster by three latching positions to the right, the control device receives three signals and determines therefrom three rotations to the right and increases the temperature by three steps. Generally, the position of the rotary encoder is detected optically or by friction contacts. Typically, two encoding elements are provided that are arranged on the rotary encoder. Said encoding elements comprise an angular-offset encoding arrangement along the direction of rotation with reference to which it is possible for a detection device to detect the direction of rotation.
In this context, DE 10 2005 025 887 A1 discloses a control unit for a motor vehicle having a rotary/push control element. The rotary/push control element is embodied in such a manner that a marking element can be moved on a display device as a result of said rotary/push control element being actuated, wherein latching positions are provided during a rotation movement of the rotary/push control element.
Furthermore, U.S. 2002/0057152 A1 discloses a control unit having a rotary element. The angle of rotation of the rotary element can be detected using a Hall sensor. A haptic notification can be output to the operating person in dependence upon the angle of rotation.
DE 10 2005 055 307 A1 describes a rotary adjuster having an incremental angle-of-rotation sensor for use in a motor vehicle. An encoding element having periodic recesses is fastened to a shaft of the rotary adjuster. The recesses rotate through the detection range of a light barrier as a result of rotating the rotary adjuster and the associated rotation of the encoding element. This causes a modulation of the analog output voltage of a photosensor. By an evaluating electronic system, it is possible to allocate an incremental angle of rotation of the rotary adjuster to the progression of the analog output voltage.
DE 10 2006 060 808 A1 discloses an angle sensor for detecting the angle of rotation of a component, said angle sensor having an annular or circular disc-shaped magnet. A Hall element is arranged within the range of the magnetic field of the magnet and it is possible using said Hall element to produce a digital signal that is dependent upon the rotary position of the magnet. In addition, an analog signal of a magnetic-resistive sensor element can be allocated in dependence upon the digital signal to a first 180° angular range or to a second 180° angular range of a 360° angular range, said second 180° angular range following said first angular range.
Finally, DE 10 2008 057 098 A1 describes a rotary adjuster for a vehicle and said rotary adjuster comprises a latching arrangement and a movement detection arrangement. It is possible using a sensor device of the rotary adjuster to detect the direction of rotation and the angle of rotation of an adjusting element.